Chapter 4 Building Conceptual Data Models


Inheritance properties

You can double-click any inheritance symbol in the diagram to display its properties:

Property Description
Name The name of the item which should be clear and meaningful, and should convey the item's purpose to non-technical users
Code The technical name of the item used for generating code or scripts, which may be abbreviated, and should not generally include spaces
Comment Descriptive label for the inheritance link
Stereotype Sub-classification used to extend the semantics of an object without changing its structure; it can be predefined or user-defined
Parent Name of the parent entity
Mutually exclusive children Indicates if only one child can exist for one occurrence of the parent entity.
Complete Indicates that all instances of the parent entity (surtype) must belong to one of the children (subtypes). For example, entity Person has 2 sub-types Male and Female; each instance of entity Person is either a male or a female

An inheritance link definition also includes the following properties, which are defined on associated property sheets:

Property Description
Generation Group of properties that affect physical implementation
Children List of child entities
Notes Description associated with inheritance link
Rules Business rules attached to the inheritance link

Inheritance display

Depending on the model notation, the inheritance symbol displays the inheritance status:

IDEF1X E/R and Merise notation Description


Standard

Mutually exclusive inheritance


Complete inheritance

Mutually exclusive and complete inheritance

 


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